Biomechanical and anatomical consequences of carpal tunnel release

Carpal tunnel syndrome is an exceedingly common orthopaedic problem in the United States. When conservative management is unsuccessful, most surgeons proceed to surgical treatment. Though the carpal tunnel release procedure is usually curative, many patients experience postoperative complications, such as scar sensitivity, pillar pain, recurrent symptoms, and grip weakness, regardless of whether the release was done through an open, mini-open, or endoscopic approach. The exact causes of these and other complications of carpal tunnel release remain unclear. Release of the carpal tunnel has an effect on carpal anatomy and biomechanics, including an increase in carpal arch width, carpal tunnel volume, and changes in muscle and tendon mechanics. We set out to review the morphological and biomechanical changes caused by carpal tunnel release with the goal of better understanding the root causes of postoperative complications. This article first reviews normal carpal tunnel anatomy and anatomic variations, then available surgical techniques for carpal tunnel release, and finally the literature on morphologic, physiologic and biomechanical alterations in the wrist after carpal tunnel release.